Method of producing printing-surfaces.



UNITED STATES PATENT orrion.

RUDOLF HAJ'EK, OF VIENNA, AUSTRIA-HUNGABY, ASSIGNOR TO HERMANN HT J'RWITZ & (10., OF BERLIN, GERMANY, A FIRM.

METHOD E PRODUCING PRINTING-SURFACES.

No Drawing.

the Empire of Austria-Hungary, have invented a certain new and useful Improved Method of Producing Printing-Surfaces, of which the following is a specification.

This invention relates to an improved method of producing printing surfaces for inanifolding documents, drawings and the like and relates to certain improvements in the known method in which the matter to be reproduced is transferred to a prepared dull vitreous and rigid surface, such as glass or the like, the' transfer being developed and prints thereafter taken by inking the vitreous surface in the usual manner.

According to the present invention the matter to be reproduced is printed, impressed or otherwise produced in a stencil or coated sheet, which may be of the kind used for the mimeograph or cyclostyle, or any other coated or (preferably) waxed sheet in which the matter to be reproduced can be impressed either ,by means of a type-writer, style, or other stencilinginstrument. The stencil is then laid on the vitreous surface which is previously rendered sensitive by treating with an acid solution consisting essentially of a hygroscopic substance such as the sugars or glycerin and hydrochloric acid together with alum or aluminium or magnesium salts or both aluminium andmagnesium salts with or without the addition of calcium chlorid or an alkaline salt.

way of example :About 20 parts by weight of a hygroscopic sugar or glycerin, about 10 parts by weight of aluminium and magnesium salts in about equal parts, and 2 to 3 parts by weight of hydrochloric acid and an alkaline salt, the wholebeing dissolved in about 65 parts of water. This solution is spread sparingly over the surface and the surface then thorough] dried by means of a small cloth, pad of wading, or the like.

The stencil is covered with a sheet of paper, linen or the like'which is impregnated with a special solution capable of producing an insoluble precipitate with the solution with which the vitreous surface is treated.

The solution may be either ammonia in which ferrogallatc is suspended or any other Specification of Letters Patent.

Application filed Novcmbcr- 2c, 1912. Seiia1No. 732,a95.

Patented J uly 15, 1913.

suitable alkaline'solution such as ammonium carbonate, or solutions or suspensions of me tallic oxids or hydrates such as ferric oxid or hydrate, or the fixed alkalis in caustic or carbonate form. Organic salts capable of forming insoluble substances in contact with the hygroscopic solution may likewise be employed iii-solution or suspension.

Apparently the salts contained in the impregnated sheet react with the aluminium and magnesium salts on the vitreous surface to form an invisible and insoluble precipitate.

Uniform contact between the stencil sheet and the vitreous surface, in-order to obtain a perfect transfer, is attained by pressingthe stencil upon the vitreous surface in any suitable manner, so that the stencil coheres to the vitreous surface.

After the stencil, with the impregnated sheet thereon, has been left a short time in contact with the, vitreous surface, it is removed, the transfer however remaining still invisible. The vitreous surface is then treated with adeve'loping solution, which also enables the blank parts of the surface to repel rinters ink on subsequent inkin The developing solution consists essential y of borates or organic acids or their alkaline salts, such as, for example, the aromatic hydrocarbons,cinnamic acid, salicylic acid, benzoic acid or. the like, the acid or salt being dissolved in glycerin or like hygro-' scopic liquid andjbeing spread thinly over the surface, which is then left slightly moist. The surface may thereupon. be inked and any desired number of prints taken in the usual manner, the surface being reinked'for each reprint. The plate 15' afterwafid cleaned by using the hygroscopic solution, previously used to repare the vitreous surface for the trans er, so that the plate is not onl cleaned, but is simult-aneously pre pared or receiving a fresh'transfer.

I claim 1 Method of producing printing surfaces,

- which consists in preparing and rendering sensitive a dull, vitreous and rigid surface with a hygroscopic acidic solution of an aluminium salt, impressing the matter to be copied in a coated sheet, laying the impressed sheet on the prepared vitreous surface, a plying a saturated sheet to the back of sai coated sheet, said saturated sheet. being saturated with a solution ;which is capable of forming an insoluble precipitate on contact with said prepared vitreous surface, applying pressure to and thereafter removing said coated and saturated sheets, and treating the vitreous surface with a hygroscopic solution which causes the unimprinted parts thereof to repel printers ink.

2. Method of producing printing surfaces, which consists in preparing and rendering sensitive a dull, vitreous and. rigid surface with a hygroscopic acidic solution of aluminium and magnesium salts, impressing the matter to be co ied in acoated sheet, laying the impressed s Ieet on the prepared. vitreous surface, applying a saturated sheet to the back of said coated sheet, said saturated sheet being saturated with a solution which is capable of forming an insoluble precipitate on contact with said prepared vitreous surface, applying pressure to and thereafter removing said coated and saturated sheets,

and treating the vitreous surface with a hygroscopic solution which causes the unimprinted parts thereof to repel printers ink.

3. Method of producing printing surfaces, which consists in preparing and rendering sensitive a dull, vitreous and rigid surface with a hygroscopic acidic solution of an aluminium salt, impressing the matter to be copied in a waxed sheet, laying the waxed sheet on the prepared vitreous surface, applying an impregnated sheet to the back of said waxed sheet, said impregnated sheet being Hnpregnated with a solution capable of forming an insoluble precipitate on contact with said prepared vitreous surface, applying pressure to and thereafter removing said waxed and impregnated sheets, and treatin the vitreous surface with a solution WilCh causes the unimprinted parts thereof to repel printers ink.

4. Method of producing printing surfaces, which consists in preparing'and rendering sensitive a dull, vitreous and rigid surface with a hygroscopic acidic solution of aluminium and magnesium salts, impressing the matter to be copied in a Waxed sheet, laying the waxed sheet on the prepared vitreous surface, applying an impregnated sheet to the back of said waxed sheet, said impregnated sheet being impregnated with a solution capable of forming an insoluble precipitate on contact with said prepared vitreous surface, applying pressure to and there after removing said Waxed and impregnated sheets, and treating the vitreous surface with a solution W i printed parts thereof to repel printers ink. In testimony whereof I have afiixed my signature in presence of two Witnesses.

RUDOLF HAJEK. Witnesses: Haws SoHUsaY, KARL HORAK.

ch causes the unim-- 

